CVE-2021-47439
In the Linux kernel, the following vulnerability has been resolved: net: dsa: microchip: Added the condition for scheduling ksz_mib_read_work When the ksz module is installed and removed using rmmod, kernel crashes with null pointer dereferrence error.
Does this matter?
Lower severity and a low EPSS score (0.22%). Track it; it rarely justifies an emergency change on its own.
Description
In the Linux kernel, the following vulnerability has been resolved: net: dsa: microchip: Added the condition for scheduling ksz_mib_read_work When the ksz module is installed and removed using rmmod, kernel crashes with null pointer dereferrence error. During rmmod, ksz_switch_remove function tries to cancel the mib_read_workqueue using cancel_delayed_work_sync routine and unregister switch from dsa. During dsa_unregister_switch it calls ksz_mac_link_down, which in turn reschedules the workqueue since mib_interval is non-zero. Due to which queue executed after mib_interval and it tries to access dp->slave. But the slave is unregistered in the ksz_switch_remove function. Hence kernel crashes. To avoid this crash, before canceling the workqueue, resetted the mib_interval to 0. v1 -> v2: -Removed the if condition in ksz_mib_read_work
- CVSS 3.1
- 5.5 MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 0.22% probability · 13th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-476
- Affected
- linux/linux kernel
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/383239a33cf29ebee9ce0d4e0e5c900b77a16148Patch
- https://git.kernel.org/stable/c/ef1100ef20f29aec4e62abeccdb5bdbebba1e378Patch
- https://git.kernel.org/stable/c/f2e1de075018cf71bcd7d628e9f759cb8540b0c3Patch
- https://git.kernel.org/stable/c/383239a33cf29ebee9ce0d4e0e5c900b77a16148Patch
- https://git.kernel.org/stable/c/ef1100ef20f29aec4e62abeccdb5bdbebba1e378Patch
- https://git.kernel.org/stable/c/f2e1de075018cf71bcd7d628e9f759cb8540b0c3Patch
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.